Post By LeroyC
Post By By6
Gaggia Classic - works then stops working?..
My 10+ year old Classic has developed a strange behavior. It works for one pull and possibly two, but it seems the longer it stays on (heats up?), causes it to stop sending water through the portafilter. The pump runs, but it sends the water through the overflow pipe and won't work again until it sits (and cools down?) for a while.
What's weird is that it works, then it doesn't, which leads me to think it's not a clogged OPV valve. Or is it?
By the way, in the past I've taken the machine apart, checked for scale blockages, installed a new boiler and descaled the machine (fairly) regularly, so I'm not completely unfamiliar with its functioning.
Anyone had this problem before?
I can pretty much guarantee two things:
1. It's the 3-way solenoid
2. Someone else will jump in here and say it's not the 3-way solenoid.
Based on what you're experiencing its most likely the actual valve, but as it could be the coil it can't hurt to test that the coil is working first. If it is do yourself a favour and buy a new 3-way valve. From personal experience it's the only way to ensure you get a result. You could remove your existing 3-way, pull it apart and manually clean it to the point it looks like new and still have the same problem. This is what I did, I even put new o-rings in, but the problem was only fixed when I bought a new 3-way.
Just wondering - did it just start happening or was it following a backflush or descale treatment? Finally, if you haven't already make sure you check out the Gaggia forum. It's called the Gaggia Users Group and has its own website. It's a wealth of info and is a must read for any Classic owner. All the best, let us know how you go.
I've rebuilt 5 commercial machines this year and ran into this problem with one of them - very, very frustrating. Nearly exactly as you describe. I searched threads and found information along the lines of what leroyc talks about in replacing the solenoid. I did this with no effect unfortunately. I then pulled each valve block apart - the solid (usually brass) body where the solenoid sits over. After some very fussy investigation, I found a tiny particle within the valve block's narrow orifices which I assume was becoming loose once the machine became warm and commenced operation (as I was only getting 1 to 2 shots out of mine before it went kaput each session). I removed the blockage and have not looked back since - it has been flawless.
You'll need to be really fussy with your investigation of the valve blocks and do it into a white bowl or similar, so that you can see what comes out when you blow air through / water rinse / pick with a paper clip / etc.
I hope this fixes your issue for good champ.
....a tiny correction - you can't pull the valve block 'apart' - I meant removing everything from it and taking it out of your machine for working on.... sorry. Ben.
I think Leroyc is on the same page.
Yeah sort of same page, but I can assure you that you are very unlikely to be able to do the same thing with a Gaggia Classic solenoid valve that's 10 years old. It's a working part that has reached the end of it's life and it's a waste of time to try and clean it out which is why I recommend replacing it.
Originally Posted by By6CoffeeRoasters
By experience can be the solenoid or a blockage inside the boiler. You can start by taking the solenoid a part and cleaning this is only two Allen Key screws, but if this does not work your blockage will be inside the boiler. Unfortunately your boiler is made out of aluminium, which tent to hold more the calcium from the water. You will need to take out the boiler and clean inside this. You will need a new boiler seal Gaggia Boiler Gasket - Di Bartoli
If you have any questions happy to help just give a call
When you say that it's sending water through the overflow pipe, do you mean the metal tube from the group that discharges into the drip tray, or the teflon tube from the OPV that discharges into the water tank ??.
If it is the first one, then it's probably the 3way valve, but if it's the latter, then it could be that the OPV is sticking in the open position.
"Just wondering - did it just start happening or was it following a backflush or descale treatment?
Finally, if you haven't already make sure you check out the Gaggia forum. It's called the Gaggia Users Group and has its own website. It's a wealth of info and is a must read for any Classic owner. All the best, let us know how you go."
Thanks, it didn't start after a descale. I have never done a backflush? Not sure about that. One time while I was doing a descale, I was finishing up the final clean water flush and the machine stopped working. Couldn't believe it. Got through the whole process, running for quite a while (should have gotten as hot as it can) and then the water just stopped flowing. Totally frustrating and confusing.
I'll post the question on Gaggia Users Group, too.
Never done a backflush? Ever? Oh dear. A 3-way solenoid valve pretty much relies on being regularly backflushed to continue to operate properly. It's a minor miracle your machine has lasted as long as it has. It also sounds like maybe you're overrunning the pump when doing flushes during and after a descale. These little vibe pumps shouldn't be run for more than 60sec at a time.
Originally Posted by Totallity
So based on all that I'd say the 3-way solenoid will definitely be stuffed and the group head probably needs a good manual clean as well.
Yes, it's the first one. The metal tube into the drip tray.
Originally Posted by deegee
I'll need to learn more about the backflush, then. Never done it, though I've done many deep manual cleanings of the grouphead and associated parts. Also, I've taken the OPV valve off and cleaned it the best I could, looking for any particles that could be causing a blockage.
Originally Posted by LeroyC
I don't run the pump for long stretches, though. When I'm flushing the fresh water through after descaling I run what would be close to a normal pull and let it sit, kinda judging timing based on the light's cycles. That was why I was frustrated after flushing with no issues for 7/8's of a tank of fresh water only to have the blockage issue show up as I was about to complete the descale/flush process!
Gaggia Classic - works then stops working?..
It really does sound like a typical case of a busted 3-way solenoid to me, especially knowing that it's never been backflushed. It's quite common for Gaggia owners to not know about the need to backflush as most of their domestic machines don't have 3-way solenoids and therefore can't and shouldn't be backflushed. In fact I think at least some of the Classic user manuals say DO NOT BACKFLUSH, but I'm guessing this is simply because it's a generic manual that gets put with all their machines. You'll find lots of info on the Gaggia forum, but in the meantime buy a new 3-way and give your group head a clean. All the best.
I would personally try backflushing.
If that fails you have two main options if you investigation pin points to the 3-way solenoid valve:
1) Try to service the innards of the 3-way solenoid valve. I know it is "non-servicable", but I have personally cracked one open to clean a blocked valve sucessfully. Just be careful not to damage the mating surface!
2) Buy new.
Also remember that Gaggia's also can fail from corrosive metal chunks settling to the bottom of the boiler if it is old. These chunks often block the passage ways. You might want to test that these pathways are not blocked on your boiler.
The only thing that I would recommend from experience is never removing the steam valve from a boiler as the normal sized gaskets never seem to seal the unit after removal.
Best of luck!
My reply to Totallity last June 13 when he posted the same problem over at GUG.
Best guess is that you can solve the issue by a detergent backflush or a 3way Solenoid overhaul or replacement.
3-way solenoid valves are definitely serviceable. They wouldn't sell seal kits for them if they weren't.
Originally Posted by metho
Same with the steam valve. Remove it from the top of the boiler if and when necessary. Replace the o-ring with a new one in the correct size. It is a bit of a trap as it's a larger o-ring than you'd expect and doesn't fit snuggly onto the inlet of the steam valve but rather sits there quite loose. When the steam valve is refitted and the bolts tightened it gets flattened to make a good seal.